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Engine won't warm up, lots of white smoke, need some help....

The reason I write that I could use some HELP is that I am on a road-trip in the 4BT Scout. Not only do I need to actually get home, but dumping out clouds of white smoke everywhere I go in Reno is a real drag....

The title of the thread pretty much explains the problem. The 4BT is putting out a whole lot of white smoke... especially on revving the engine, but all the time really. Also, the coolant temperature gauge shows that the coolant temperature is not getting very warm, compared to "normal". (This is the stock gauge from the Scout, so no actual temp numbers on the gauge face)

Here are a few other details...
A few days ago on the way through Arizona I plowed into a pretty big snow bank, and the wire to the electric fan got ripped. As far as I know, that fan has never turned on, so I didn't fix the wire at that point. Then, later in the day, I was waiting in a really long, slow line to get into the Grand Canyon and the coolant temp gauge showed higher than ever before, but still only about half-way up the gauge. When the gauge reached that point it stabilized, even though I was still in line for another 10 or 15 minutes.

Today I put a piece of cardboard in front of the radiator, completely covering it. This helped the temps get up a little higher, but they are still considerably below normal. This might have helped the smoke a little, but not that much. I also changed the fuel filter (even though my fuel pressure gauge said I didn't need to) and this helped a little, but not much. Still lots of smoke.

I checked the oil, and I see no evidence of coolant at all. It's also not low. Also, I smelled the smoky exhaust, and it didn't smell like oil, and it didn't really smell like diesel either. It had a smell, I am just not sure what it is.
Engine power is normal, EGTs are normal, boost is normal.

Could the thermostat be stuck open??

I need the truck to get around, and to get home. Any help would be appreciated.

Thermostat stuck open would be my first thought, too, as long as it's not changed behavior in any other way (suddenly down on power, much harder to start, etc.)

I'm assuming you're not loosing coolant, right?

A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly.
Specialization is for insects.
- Lazarus Long, as written by Robert A. Heinlein.

Originally Posted by BobS

You need to first confirm the problem BEFORE you start buying and replacing parts.

Thermostats getting stuck are as frequent (or infrequent, depending on your outlook on life) with the 4BT as they are with any other engine.

Anymore, I don't install one unless I check it beforehand. I've encountered too many brand new thermostats that weren't quite all they should have been in the last few years.

Another possibility for white smoke is coolant.. Does the smoke smell "sweet"? If so, then you've likely got a blown head gasket or cracked head. And if you run these things with a low coolant level, you can crack the head in short order.. (Most likely between the injector bore and the valves.) These folks that run them for more than about 30 seconds without coolant on some of the YouTube videos are really running a risk of a cracked head, even though the block doesn't get warm to the touch.

IIRC, the thermostat for the 4BT is the same as for the 6BT of similar years if you're hitting an automotive parts house.

A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly.
Specialization is for insects.
- Lazarus Long, as written by Robert A. Heinlein.

Originally Posted by BobS

You need to first confirm the problem BEFORE you start buying and replacing parts.

Well I went down and checked the coolant. It is low, but not super-low... about 3 inches down from the filler neck.

However the coolant looks pretty awful. It's sort of brown and grimy. BUT, I did add some Bar's Leaks a few days ago, and the coolant looks more like Bar's Leaks than oil. It also does not really smell like oil. Also, there is NO sign of coolant at all on the oil dipstick.

Thermostats are easy and pretty cheap, I'd do that first and see what happens. I also suggest getting the right one if you can, not the cheaply made, stamped metal ones you get at the parts houses. Of course, a properly functioning one is really all that matters at the moment!

Again, does the exhaust haze from about three feet from the pipe have a sweet smell? You already indicated that the coolant level is going down and an audible engine miss. These are the usual signs of a head gasket failure.

1. Top off the coolant ,start up the engine and check to see if you have air bubbles ,if so your head gasket is bad.
2. Any time you add stop leak to a radiator you have a chance for stat to stay open.
3. Do you have heater ,cool to warm ?
4. As noted the cheap o stat that you buy @ the auto parts stores are cheap for a reason.Some are better than some but are way different than what Cummins uses.

With running the engine under temp ? which you didn't list ,it could do a lot of DAMAGE .You need to fine out what going on before you keep running the engine.

To be honest, this is turning into a very hard trip with the Scout. It is having an infrequent problem with no boost/high EGT's which seems to be related to which gear I am in (I know that sounds crazy, but the problem will go away if I change gears or go into neutral for a while). I haven't even gotten into discussing that problem because it feels less pressing right now.

And just tonight, the fuel shutoff solenoid totally stopped working. Turned the key to off.... engine still ran. Pulled the wire from the solenoid.... engine still ran. Guess I'll be popping the hood and reaching for the lever until I get home and can hook up a cable.

I am going to suggest checking something totally different. You said you ran into a snow bank. Check your fuel lines. Into lift pump and filter housing. I had a very similar situation on a 6bt about 2 years ago. Make sure you check inlet fittings, Mine would do it when it was warmer out, but it wouldn't quit if it was colder.

A hard trip back

I have just driven 1200 miles back from Reno. I was able to keep the engine temps in the normal range by covering approximately 95% of the radiator with cardboard.

The amount of smoke gradually increased over the last few days, and it is absolutely burning oil. It smells strongly of oil and I had to add about a quart of oil every 300 miles or so to keep the level good.

THIS INDICATES A FAILED HEAD GASKET, RIGHT ??

I need to know what this is before I tear into it.

(I don't think its the lift pump or lines because they are new, burly, and untouched by the snow bank. I don't think it's the IP because the truck basically ran very strong, despite temperature instability and smoke.)

Well, unfortunately, oil consumption could be any number of things besides a head gasket, and in truth, that would be pretty far down on my list of suspicions.

Bottom line, you need to run a leak down or a compression test on it and see if you can figure anything out there. You need to either plan on tearing things down till you find the problem, or run some diagnostics first to give you some direction.

From your description of the details, it could be headgasket related, but if you overheated it without knowing it, then it could be the head, possibly a burnt piston, or any number of other things. Just how sure are you that the temp guage reads correctly. that little duration ov elevated temps, might have been higher than you realized, and unfortunately, you may have done some real damage.

My vote is for a cooked turbo. Baked the seals out of it and now it's burning oil from it. Could also have damabed the bearings. Causing lack of power from low boost, also give you high egt's cause of it. I agree with dahoyle, prob not head gasket, I'd be lookin at the turbo first, then do leak down and compression test.

1994 Dodge Dakota Ext Cab 4x4. 4BTA 553 and 1032ft/lbs torque, 11.43 at 118mph 1/4.
There are no stupid questions, but there are a LOT of inquisitive idiots

My thoughts/theory now points toward a possible plugged piston oiler nozzle which caused the piston to expand in the cylinder which could have caused the engine to initially overheat. Then after everything cooled back down the cylinder slightly/partially misfires due to compression loss from either a cracked piston or a gouged cylinder wall. This in turn causes less overall heat to be generated by the remaining three cylinders and now permits oil to pass in the cylinder into the exhaust where it is burned by the other three cylinders exhaust causing blueish/white smoke.

The turbo was acting strangely during the entire trip. While it is tempting to think that all the problems might be caused by a funky turbo, the fact is that the turbo started acting strangely BEFORE the other symptoms appeared. This suggests that it may not be the sole cause.

Here is what the turbo was doing: Sometimes when slowing down, there would be a short noise which sounded like a shaft sloppily spinning in a bearing (if you have ever put a die-grinding burr bit in a hole that was slightly too small, and had the high-speed bit "spin" uncontollably around the hole, it sounded sort of like that). Typically, after hearing that noise, the next time I stepped on the gas there would be A) no boost, B) rapidly rising EGTs, and C) a sound like a turbine winding up, which was proportional in pitch to the engine RPMs. Interestingly, this "turbine-winding-up" sound would occur only when the turbo was apparently not working. Sometimes if I switched gears, bringing down the RPMs, or more reliably if I just went into neutral and let the RPMs come down to idle for a few seconds, the problem would go away, i.e. the turbo would start working again.

I do not really understand the mechanism that might be causing this particular problem, at least in part because I have never taken apart a turbo. But my best guess (some of your guesses will invariably be better) is that the bearings went bad or they were not getting oiled or something like that, and the turbo was somehow "sticking" intermittently.

It did occur to me on the trip that the problems might have been caused by whatever was going on with the turbo, BUT.... I cannot see how the turbo could explain the other main symptoms.

These symptoms are:
1) A clear "missing" sound from the engine
2) Engine's inability to maintain heat
3) Oil-smoke also coming from the crankcase breather, from oil dipstick tube, and oil-fill cap (all pointing to oil-smoke in crankcase)

These point towards SOMETHING else. BobS's theory sounds good to me. I will have to get into it.

I"m going to say you got more then one problem. The noise you heard from the turbo was probably the compressor wheel grinding against the compressor housing. In which case that turbo is finished. Either find a new one, rebuild that one, or get a good used one. Mabye one of the fins broke off the compressor and went through the engine?? It could cause some damage, scored a cylinder or something. I'd be lookin at that turbo first since it's the easiest to diagnose and then change.

1994 Dodge Dakota Ext Cab 4x4. 4BTA 553 and 1032ft/lbs torque, 11.43 at 118mph 1/4.
There are no stupid questions, but there are a LOT of inquisitive idiots

Reading through the posts from a distance here it makes sense to me that the major problem is the turbo.

It was already mechanically acting up, possibly already causing probelms too. The impeller is held to shaft with a nut, and of course it's very tight tolerances. If somehow the nut loosened then the impeller can drag on housing. This can also allow the shaft to walk in the bearings or wipe whatever thrust washers are used.

Possibly hitting the snow bank in some way impacted the turbo by shock, increasing problems? May even have knocked boost lines loose, or jammed the exducer from exhaust slamming into snow. Snow is soft, yeah, but it only compresses so much.

I think your cylinder tempreature would be lower if there's not enough oxidant in charge to fully ignite mixture. Seems that might contribute to lower operating temperature. I suspect that's a result of something different though.

It's obvious that I need to pull that turbo and inspect it. By checking inside the exhaust manifold, I suppose I could see whether the oil is originating from one of the cylinders rather than from the turbo.

The "missing" sound and the oil-smoke in the crankcase still suggests a problem with a cylinder to me.

A leak-down test also seems to be in order. I just educated myself about how to build a tester and perform a test. Guess I'll be doing that soon.

The more I think about this, the more I can't help but think that the significant amount of blow-by gases in the crankcase, and less conclusively the "missing" sound, indicate that there is a problem inside one of the cylinders.

Turbo is toast. Tons of side-to-side play, evidence of vanes contacting the housing. There was also oil in the crossover tube.

I hoped that would be it. Went ahead and pulled injectors and did a leakdown test, and the results were not good.

5 out of the eight valves are incredibly leaky, losing air at something like 15 psi per second. 2 more are a little less bad, and only one seems to hold air.

I tried to decide whether to pull the head with the engine still installed, or yank the whole drivetrain... Decided to yank the whole drivetrain. It'll be a lot easier to work on, I can do the leaky rear main seal, sort out the fuel shutoff solenoid, probably do the KDP, etc.

At least I know how to take the damn thing out!

Sometime this weekend, I should have the engine out and the head off, and then I will see whether the block needs to be bored. At that point I will start asking questions about how far down into the crankcase / rotating assembly I really need to go.

I hoped that would be it. Went ahead and pulled injectors and did a leakdown test, and the results were not good.

5 out of the eight valves are incredibly leaky, losing air at something like 15 psi per second. 2 more are a little less bad, and only one seems to hold air.

Did you make sure that the valves were completely closed?? if the valve's closed, try tapping on the tip of the valve when you have airpressure in the cylinder, see if that helps slow the leak. (it will help seat the valve 100% against the head.)

1994 Dodge Dakota Ext Cab 4x4. 4BTA 553 and 1032ft/lbs torque, 11.43 at 118mph 1/4.
There are no stupid questions, but there are a LOT of inquisitive idiots